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An In-Depth Review of Canon's RF 600mm & 800mm f/11 IS STM Lenses
Canon raised a lot of eyebrows when they announced the extremely affordable RF 600mm & 800mm f/11 IS STM lenses. “An 800mm lens for $899??? But it’s f/11??? What’s going on here??” Canon has so far been unique in this sub-$1,000 venture, especially considering the 800mm lens. What are the real trade offs with these smaller & cheaper f/11 600mm and 800mm lenses?
Canon raised a lot of eyebrows when they announced the extremely affordable RF 600mm & 800mm f/11 IS STM lenses. “An 800mm lens for $899??? But it’s f/11??? What’s going on here??”
Canon has so far been unique in this sub-$1,000 venture, especially considering the 800mm lens. As far as I can tell from looking at the websites of Sony, Nikon, Panasonic, Sigma, Rokinon & Samyang, the only other major camera or lens manufacturer that actively produces an 800mm lens is Nikon, and it costs over $16,000. Canon’s 800mm f/5.6 lens costs around $13,000. So what are the real trade offs with these smaller & cheaper f/11 600mm and 800mm lenses?
I own both the 600mm and 800mm f/11 IS STM lenses and use them both, but this article looks primarily at the 800mm since it lets me test more extreme focal lengths.
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Can They Really Produce Sharp Images?
I wanted to see if these lenses are sharp, and I started with a very controlled environment that you probably wouldn’t be in whether you’re trying to have fun or make money. I mounted the 800mm f/11 on a tripod indoors, attached a wired remote trigger to my Canon EOS R5, and focused on some playing cards that were about 20 feet away. The distance of 20 feet is important, because 19.69ft is actually the minimum focusing distance for the 800mm f/11 (it’s 14.76ft for the 600mm). I got as close to the cards as I could while still being able to focus on the King’s face. I took one shot with the stabilizer on and one shot with the stabilizer off, both using Electronic 1st curtain shutter. The camera settings were ISO 100, 800mm, f/11, 2.5 seconds. Here are the results of those two shots:
When I looked at the first image on my computer screen (when the stabilizer was off) I had absolutely no complaints about image sharpness. In fact, I was impressed. No one should be complaining about the sharpness of this 800mm lens for the price! I can see more detail in the playing cards from 20 feet away that I would typically notice if I was holding the card in my hand.
The image with the stabilizer turned on showed a little bit of blur. I assumed this would happen because I could see it in the camera’s LCD before I took the shot… the image moved around ever so slightly and constantly, and it is clear that stabilizers in an 800mm lens are not designed for long tripod exposures. I have accidentally left the stabilizer on when using a Canon RF 15-35mm wide angle lenses on a tripod and had no detrimental effects on sharpness, but with these super-telephoto lenses the stabilizer is definitely designed for faster shutter speeds during hand-held shooting.
Here are cropped versions of the above photos with the stabilizer on and off:
You can see in the above cropped images that when the stabilizer is off it is sharp enough to see the tiny fibers on the top edge of the card and the texture of the card itself. But when the stabilizer is on, it is slightly blurry.
Call me crazy, but I wanted to see if the image was still sharp if I threw a Canon Extender RF 2x on the 800mm lens. Since I was already stuck at f/11 with the lens, adding a 2x Extender will cause me to be stuck at f/22! I did an 8 second exposure instead of a 2.5 second exposure. I also moved back about 10 feet in order to keep a few different cards in the frame. Here is the shot from about 30 feet away with a 2x Extender, both uncropped and cropped:
Once again I was impressed! Even at when using a 2x Extender to achieve 1600mm, the image was sharper than I expected. From 30 feet away I can see the tiny fibers on the top edge of the cards, the texture of the cards, and the texture of the fake plant leaf behind the cards.
Thumbs up for Canon’s glass quality & sharpness, for both the lens and extender!
How Good are those Stabilizers? Hand-Holding Shots for Stationary Objects
One of the biggest challenges with 600mm or 800mm lenses is camera shake. The tiniest movement or vibration can cause your image to turn out blurry. Even the shutter or mirror in your camera can cause the image to be blurry, which is why I used 1st curtain electronic shutter for the longer tripod shots and electronic shutter mode for shots quicker than 0.5 seconds. Very fast shutter speeds and lens stabilizers can overcome vibration from a camera’s mirror or shutter, but since I am trying to specifically test the stabilizers in these lenses at different shutter speeds I wanted to eliminate that potential cause of vibrations.
When you are hand-holding such a long lens for the first time, you might be surprised how hard it is to keep it still! The longer the lens, the more the subject will appear to be jumping around. This is why there is a “rule” about keeping your shutter speed about twice as fast as your focal length when you are shooting with your camera in your hands rather than a tripod. For example, if your lens is 50mm you’d want to use shutter speeds at least as fast as 1/100th of a second. If your lens is 15mm, you should only need a shutter speed of 1/30th sec. Does this rule still apply at 800mm? Let’s find out!
For the next test I found a couple of frogs playing a game, and payed them $20 to sit still for a few minutes (just kidding). I took at least 10 shots at each shutter speed with the stabilizer on and off. I used autofocus to focus on the left frog’s eye before each set of shots. Even though I was stuck at f/11 the background is blurred nicely, due to the fact that I was only about 20 feet away at 800mm. I adjusted exposures to make all the images somewhat similar, because in some shots I had slowed down the shutter speed without being able to change the aperture or lower the ISO further. I also had to move the frogs into the shade once I was testing slower shutter speeds.
For each set of photos, I had the Canon EOS R5 set to continuous shooting with the electronic shutter, which means it was firing at 20 shots per second. I just held down the shutter button until I got at least 10 photos. One thing to note on these non-stabilized shots is how much the photos jump around between shots, despite the photos only being 1/20th of a second apart! It’s a good indication of how hard it is to hold an 800mm lens steady.
My first test set was shot at 800mm, ISO 1000, f/11, 1/1600th sec, stabilizer off. When I looked at the 1/1600th sec shots with no stabilizer, it looks like the “rule” of using a shutter speed twice as fast as your focal length generally held up. I had 17 photos at this shutter speed and they all looked nice and sharp.
Now let’s see how a 1/800th sec. shutter speed did at 800mm since that “breaks the rule:”
Initially when looking at the 1/800th sec. shots on the computer I thought I “perceived” motion blur, but when I zoomed in I couldn’t necessarily prove it. So it seems like 1/800th of a sec. still produces usable images at 800mm, or have such a minor loss of sharpness that most people wouldn’t notice it.
At shutter speeds of 1/200th and 1/400th of a second it is hard to see the motion blur when looking at the whole images, but most of the images lose sharpness at these slower speeds. Here are four of the images at 1/200th:
Here are a couple crops to show the blur up close. One of these shots at 1/200th is fairly sharp, and the other shows a bit of blur:
At 1/100th of a second I took 13 shots with the stabilizer off, and only 1 lucky photo out of 13 was sharp. Once I got down to 1/50th of a second all 12 images I took had noticeable motion blur, and most of the photos were basically unusable:
To summarize the results of the non-stabilized test shots at 800mm:
1/1600th of a second produced all sharp images
1/800th of a second produced mostly sharp images, maybe a little blur creeping in on some
1/400th of a second produced a little motion blur on most images
1/200th of a second produced more motion blur than 1/400th, but still had a couple usable images
1/100th of a second produced 12 blurry images, but I had 1 lucky sharp one in there.
1/50th of a second produced 100% blurry images
So ultimately, the shutter speed that is double your focal length would be the safe choice if you were only taking one photo of a stationary object with the stabilizer off. If you take 20 shots per second like I did in this test, you could get away with lower shutter speeds than the rule suggests if your subject isn’t moving at all and maybe get a couple lucky sharp ones in there. =)
Now let’s see how far we can push shutter speeds with the stabilizer enabled. I am doing these tests with a Canon EOS R5, which has in-body image stabilization. This means if you were to put the same lens on an EOS R which does not have in-body image stabilization, you might not want to push the shutter speeds as low.
Let’s continue with shutter speeds of 1/50th of a second, but this time with image stabilization enabled:
When looking through these 1/50th sec. shots on my computer the one that had the most blur was the first image, captured right after I pushed the shutter button. I could have had a steadier first image if I had used the camera’s 2 second timer, and if I was trying to take a steady single shot that’s definitely what I would do. But generally speaking the stabilizer allowed me to shoot at 1/50th of a second. Also notice how the composition doesn’t jump around much at all! The stabilizer is making up for my slight hand movements that were clearly present in the non-stabilized galleries earlier on. Taking shots with the stabilizer on at 1/100th resulted in all sharp images as well, including the first shot as I was pushing the shutter button.
I ended up taking 12 images in less than a second with a shutter speed of 1/25th, and the photos ranged from being sharp to having a minor amount of blur. Here is a crop of a couple photos at 1/25th from one of the sharper photos and one of the blurriest photos:
So using 1/25th sec. shutter speed for stationary subjects is fair game with this lens, especially when using continuous shooting (aka burst shooting) drive modes and an electronic shutter. As quick as the R5 shoots photos you will probably end up with a couple sharp photos in less than 1 second of shooting.
My test results at 1/13th sec. brings me to the end of our shutter speed stabilization tests, because all of the photos had a little motion blur. The amount of blur was very consistent at 1/13th, and the photos weren’t necessarily unusable but they definitely weren’t perfectly sharp.
To summarize the stabilizer tests with the Canon RF 800mm f/11 IS STM Lens:
Most or all photos will be sharp when shooting at 1/50th of a second or faster when the stabilizer is on and your subject is still (no animals or people)
You can get away with shooting stationary subjects at 1/25th of a second if you are burst/continuous shooting (hit or miss sharpness)
1/13th second exposures and slower will probably have minor motion blur in all images
You would probably never want or need to be at ISO 100 with a 600mm or 800mm lens like I was in these tests, because most subjects you photograph are going to be moving so you’ll want very fast shutter speeds. Even flowers move in the wind. If you are using these lenses you will probably be using higher ISO’s because subjects move across the frame quickly at super-telephoto focal lengths. The stabilizers are great, but they don’t stabilize the motion of your subject… they only reduce the effect of movement created by your hands holding the camera.
One Interesting Scenario where the RF 600mm and RF 800mm f/11 Lenses Differ Significantly vs. the Canon RF 100-500mm f/4.5-7.1L IS USM
One interesting thing I’ve discovered with these lenses is the way they handle bright light sources in low-light scenes. To illustrate the issue, I took the same shot with the Canon RF 800mm f/11 lens and the Canon RF 100-500 f/4.5-7.1L Lens with an RF 2x Extender attached to the 100-500 at a lighthouse at night. Both shots were taken back to back with the same camera with a tripod in the same location with the same white balance settings:
Since the RF 800mm f/11 has no aperture blades it renders the glow from lightbulbs along the catwalk as round circles of light, whereas the RF 100-500 f/4.5-7.1L captures the lights as stars with 18 points since that lens has 9 aperture blades. Canon’s user manual for the RF 600mm & 800mm states:
“ … Color flare might appear around the light source depending on shooting conditions…” and “For scenes where a light source is inside the screen, colored flare may occasionally appear as a halo of light around the light source.”
Most photographers will probably prefer the look of lenses with aperture blades when rendering light bulbs in night scenes over bladeless Diffractive Optics lenses like the RF 600mm and 800mm. But most people will not be using these lenses at night, so that shouldn’t be a deal breaker.
Sample Gallery - Photographing Live Animals at 1600mm
For the live animal sample gallery I wanted to take things to the extreme and see what kind of ISO’s and shutter speeds I would be using if I was hand-holding 1600mm, so I attached the Canon RF 2x Extender to the RF 800mm f/11 and took my Canon EOS R5 camera to the zoo. I found the easiest way to walk around photographing animals was to simply put the ISO on Auto with a range of up to 12,800 and control shutter speed as desired. If the camera got tricked by the lighting situation I adjusted settings as needed. I used Animal Eye Autofocus the whole time, which usually made focusing a breeze.
Here is the sample gallery with settings embedded in the photos. None of these photos are cropped at all:
Since this was my first time walking around shooting live animals handheld at 1600mm & f/22 I was slightly concerned about using ISO’s ranging from 3200 to 12,800. I assumed that the noise would be distracting enough to make the photos unusable, but I was impressed with how well the Canon EOS R5 handled it. I had the noise reduction slider in Adobe Lightroom typically between 25 and 40, and that seemed to be enough to make the noise acceptable at these high ISO’s. The combination of high ISO’s and a little of Adobe’s noise reduction allowed me to maintain fast shutter speeds for motion-stopping photos even if the animal was moving.
Initially I didn’t consider trying to photograph animals if there was a chain link fence between me and the animal, but then I tried with the mountain lion and found that the chainlink fence was so out of focus that it didn’t really show up in the image (though it may have impacted sharpness slightly). I also tried it with the tiger and was again fascinated at how the fence was so out of focus it didn’t appear to block the tiger.
These lenses will be a lot of fun for people who want to get into wildlife photography for less than $900, especially if you have a Canon EOS R5, EOS R6 or newer. I imagine this experiment would have been a little more challenging with the Canon EOS R or RP, as those cameras have older sensors and don’t have Animal Eye AF.
Keep in mind I was photographing animals in broad daylight on a beautiful, sunny day. If it was darker outside I would expect autofocus to be slower and less accurate at f/22, and I would have to make some sacrifices with ISO or shutter speed with increased risk of noise or motion blur. For that reason I would imagine it could be difficult to shoot wildlife in the woods with these lenses, but that is an experiment for another day!
Conclusion
Pros of Canon’s 600mm & 800mm f/11 IS Lenses
Glass is surprisingly sharp considering the price & focal length
Stabilizers allow for hand-held shooting
Extremely affordable
Great for learning the challenges of super-telephoto photography
Lots of fun for bird & wildlife enthusiasts who don’t want to drop $13,000+ on a lens
You can add an RF extender for extreme telephoto focal lengths
Autofocus works great in the bright daylight
Cons of Canon’s 600mm & 800mm f/11 IS Lenses
You’re stuck at f/11 (can’t go lower or higher)
Diffractive optics with no aperture blades means lightbulbs at night could flare and won’t have pointy stars like people may prefer
No lens hood or case included
No rotation collar for using camera in vertical position on a tripod (you’d have to put some type of L-bracket on it)
No weather sealing like the higher-end Canon “L” lenses (don’t use outside if there’s a possibility of precipitation)
Products Mentioned in this Article
The Good, the Bad, & the Beautiful - Using Teleconverters & Extenders
The Benefits, Disadvantages, & Considerations of Using Teleconverters/Focal Length Extenders with your Lenses.
The Benefits, Disadvantages, & Considerations of Using Teleconverters/Focal Length Extenders with your Lenses
This page contains links to products, so if you find this site useful and use a link to make a purchase, I’ll get a small commission. As an Amazon Associate I earn from qualifying purchases. Enjoy!
So you wish you had an 800mm lens, but they can be a little pricey. Or, maybe you already have a 70-200mm lens and just want some extra focal length occasionally, but not frequently enough to justify the purchase of an additional lens. Depending on your photographic intentions, an extender (some call them teleconverters) might be the perfect fit.
You typically install the teleconverter on the lens first, and then attach the lens (with the teleconverter) to the camera body. The effect this has is essentially a magnification of what is showing in the center of your telephoto lens, effectively increasing your focal length. If you install a 1.4x extender you’ll see a 40% increase in focal length, and with a 2x extender you’ll see your focal length double. Different camera manufacturers have compatibility charts to show you which lenses the extenders are compatible with, you make sure you check their specifications to make sure your lens is compatible.
The Benefits
Teleconverters are a really a great option for a number of reasons. If you want to travel somewhere to photograph a subject at 800mm but only have space and weight limit for a 100-400mm lens (Canon’s EF 800mm f/5.6L IS USM lens is 10 lbs & 18 inches long vs. the EF 100-400mm f/4.5-5.6L IS II USM which is only 3.5 lbs & less than 8 inches long), you could add a 2x teleconverter to your 100-400 zoom to attain 800mm in a more travel-friendly package.
Another obvious benefit is the price. Using a teleconverter to get you above 600mm is going to be a fraction of the cost of buying a lens with a focal length over 600mm.
Teleconverters also open up possibilities that otherwise would not be possible. For example, if you own a Nikon AF-S FX NIKKOR 200-500mm f/5.6E ED, you could pop on one of their teleconverters and carry around a 400-1000mm zoom lens!
Everything looks better at 1000mm! This photo of the Lighthouse in South Haven, Michigan at sunset was taken with a 2x teleconverter on a 100-500mm lens.
The Disadvantages & Considerations
Fortunately for teleconverter users, the sharpest part of a lens is typically the center, which is what extenders are magnifying. That being said, images produced by a dedicated 800mm lens are going to be sharper and cleaner than a 400mm lens with a 2x teleconverter. Considering the price difference, that should be expected! Teleconverters can magnify lens imperfections like chromatic aberration and softness, whereas an enormous 800mm lens with an equally enormous price tag is designed to be tack-sharp at its focal length.
The more noticeable disadvantages of teleconverters are all related to the fact that they reduce the amount of light the lens captures by preventing you from using the widest aperture the lens could otherwise offer. If you think about how big the glass is on an 800mm f/5.6 lens compared with the size of the glass on a 100-400mm f/4.5-5.6 lens, a loss of lens speed makes sense, because the aperture number (or f-stop) is the focal length divided by the diameter of the entrance pupil. Since a teleconverter increases the focal length without increasing the diameter of the lens glass, the aperture ratios are all higher. This means if you put a 1.4x extender on a 100-400mm f/4.5-5.6 lens, you will now have a 140-560mm f/6.3-8 lens. If you put a 2x extender on a 100-400mm f/4.5-5.6 lens, you’d now have a 200-800mm f/9-11 lens.
Considerations for the reduction in lens speed include:
Autofocus might be slower, limited, or unavailable, depending on the extender and lens combination
Camera shake will be more of a concern since you are using longer focal lengths and cannot use wide open apertures
A DSLR’s optical viewfinder will be noticeably darker, because you don’t have access to the widest aperture as you would without the extender
Manual focusing might be more difficult in low light whether using an optical viewfinder or the live view on a mirrorless or DSLR camera, because live view & electronic viewfinders will be noisier due to the slower lens speeds
Since most of the disadvantages of using focal length extenders/teleconverters are related to reduced light, that will be what most people should consider when deciding whether or not to use one. If you rely heavily on fast autofocus or use autofocus to track moving subjects, a teleconverter might be more difficult or impossible to use. If you are hand-holding the camera in lighting conditions other than bright daylight, ISO might have to increase enough to add noise to your photos.
If you’re able to use a sturdy tripod while shooting it will help negate some of the effects of the slower lens speeds and longer focal lengths.
Alternatives
There are alternatives to using teleconverters to zoom into far away subjects without slowing down your lens. One of those would be to use a high-megapixel APS-C camera. Since APS-C cameras have a crop factor of around 1.5 or 1.6, you could put your full-frame compatible lens on a compatible APS-C camera and get 1.5x the focal length without losing lens speed and auto focus capabilities. Of course, this would be a useless exercise if you own a 61-megapixel full frame camera and throw one of the full-frame compatible lenses on a 30-megapixel APS-C! But, if you’re comparing a 30-megapixel full frame with a 30-megapixel APS-C, it might be useful to get 1.5x longer focal length on the APS-C.
Another option would be to simply use a high megapixel camera and crop the image in post-processing. Since Canon, Nikon, Fujifilm, and Sony all make at least one model of camera body that is at least 45 megapixels, you could crop the image significantly to make it look like you used a much longer focal length, and still have enough detail to use the image for many purposes.
Hopefully that gives readers and focal-length enthusiasts a better idea of what teleconverters/extenders can do, and how they affect camera use. As mentioned at the top, if you found this article helpful and use a product link to make a purchase, I’ll make a small commission. Thanks!
